I remove documents from my PlayBook by connecting to the WiFi network on my Mac using the "smb://" method and drag them to my trash. That's only if i can't figure out how to delete them internally.
I have the same problem. I...
1) opened docs to go and see no documents
2) tapped on browse and see all my documents double
3) tapped the pencil icon near top right of screen and select a document (it gives me two options after I select a document: cancel and open)
4) tapped the bin on document I wish to delete and cannot delete it
I have removed all documents from my playbook, using the device manager
I do not have problem deleting files from Adobe, Docs to Go or even in File Manager, so cannot duplicate this problem.
I do have troubleshoot suggestions though for those that have problems - is it files downloaded from Dropbox or Bridge or maybe open in other apps? Maybe it is stored in a folder which will not allow to delete from app - you have to delete it only direct from folder??